As a 40year old adult who has had eczema since a baby, and never grew out of it I consider myself to have good knowledge about how to manage it. But, I don't have a child with eczema so my advice is just from personal expereince rather than looking after a LO with the condition.
Ditto Winged Victory on moisturising. Even if the skin is weepy it needs moisturising. Trust me on this one. Moisturising is particularly important because hydrocortisone or steroid creams dry out the skin. You may have been given an ointment rather than a cream because the ointment is more moisturising. Every time you apply the hydrocortisone/steroids ( and do apply it, you have to use them to keep flare ups under control) use moisturiser too. Moisturise At least twice a day. The moisturiser doesn't have to be expensive, or organic etc etc.I use Cetraben, Aveno cream (both available on prescription if you ask your GP). My skin hates E45, Nivea, Johnsons baby lotion, but other brands have been fine. Try different things and see what works. Don't just follow what works for others people, trial an error on your baby is the only thing to try (sorry, this will take time). I mean E45 claims to be really eczema friendly but I know several people with eczema who can't use it. I find Coconut oil is nice and soothing, and so is olive oil, but it is really greasy so it's only really an option to use it at night time, wear pjs, and wash off in the morning, or what I do if my skin is really dry, apply it half an hour before a shower/bath.
Re how quickly will you get a reaction. It depends, but for me it's within a couple of hours for something I put on my skin. I know there are a few dietary things that make my skin worse (alcohol, caffeine ) and those reactions take longer- I usually have tight red dry skin the next day if I've had too much of either. With a bad moisturiser, or a detergent that doesn't agree with my skin, I could get hives (like nettle rash) which are really itchy, or skin will just be really red dry and itchy. Again though, different people have different reactions.
A lot of the time when I was growing up, it was a case of working out what had caused the problem...we had pets, I played outside a lot in long grass, wore wool jumpers and tights, the carpets were wool, and I had loads of different skin products.. it was a mine field. Now I know that animal hair, grass pollen, wool, and scented products can all be triggers. A general tactic when near any of those things is to cover myself in cotton. I always have a long sleeve cardigan on me on a sunny day, just incase the pollen gets me itchy.
Also agree about not using scented products, and be careful about laundry products. I use Fairy laundry liquid and, if I really needed it, Comfort softener. My skin had a massive reactions to Arial... but that was 30 years ago now.
Check what baby wipes you're using. Again go for really skin friendly ones, and try different brands. My hands aren't good with a lot of wipes, and as with moisturisers, it's just pot luck what works, you need to try different ones and stick with what works. It honestly doesn't need to be organic/homeopathic blah blah, it's just use what works. Often cheap= simple ingredients. As a student I used a lot of Superdrug own brand moisturisers, they worked and didn't irritate my skin. Can you just use cotton wool and water for most of the nappy changes and wipes only when not near a sink?
Cotton, cotton, cotton. Don't use any wool...not even something that has 5%wool. Do your carpets have wool I them? How about cushions, or sofa covers, or blankets? Keep LO's skin away from wool. ...just sit on a cotton blanket instead will be fine. I found that sitting on a towel on top of the carpet worked well if I knew I would be sitting on the floor.
My mum used to bandage my problem areas so I couldn't scratch them at night...usually knees/elbows/wrists/feet. I also wore cotton gloves at night she. I was a bit older, but agree with the person above who suggested socks on hands at night would help.
Re baths. My skin actually really benefits from a bath . I think it helps to slough off the dry skin, which can sometimes get a bit built up with moisturisers, in a gentle way. I don't use soap, i just add a handful of table salt (it has antiseptic properties) to the bath, sometimes some oilatum, soak for about 20minutes, gentle rub a flannel all over, get out, pat dry and moisturise. My skin always feels a lot more comfortable after a bath than after a shower.
For the flare up on your LO's face, I would bath get a bowl of warm water with a table spoon of salt dissolved in it. Use cotton wool to wipe his face. Apply the hydrocortisone (yes, continue to use during a flare up...3 days is usually the advice right? If it's not sorted after 3days you should go back to GPfor something stronger ), and apply a a moisturiser. Even if the skin is weepy, it needs moisturising .
I've never heard of dermotherapy sheets . 100%cotton bed sheets work for me. I have synthetic fibre pillows, and no feathers in the duvet either.
I seem to have ranted on a lot here, but honestly, once your I know what to avoid, ie what triggers the condition, it will be a lot easier to manage. HTH